[spdustin]

Yes, especially in older homes or homes with poor grounding. Lightning can discharge through water supply lines[0]. There are even cases of toilets exploding due to lightning strikes[1]. (Google for more)

Sure, it's exceedingly rare. But it's also exceedingly easy to avoid. I've taught my kids that some decisions are easier when defined as binary rules; judgment calls in cases like this just don't offer any tangible benefit other than "I showered an hour earlier than I would have otherwise."

[0]: https://www.weather.gov/safety/lightning-indoors

[1]: https://fox8.com/news/lightning-blows-up-toilet-after-travel...

MythBusters even did a bit on it. They rated it "plausible".

[lxgr]

On the other hand, I wonder if you might be teaching a bad lesson about neglect of probability [1] here. The shower itself is probably orders of magnitude more dangerous by itself.

I'm wondering because I am also unsure myself if I should be concerned about lightning when showering, or whether it's statistically speaking an absolute waste of time :)

[1] https://en.wikipedia.org/wiki/Neglect_of_probability

[KeplerBoy]

It really depends on your housing situation.

If you live in the lone, old house on a barren hilltop that gets struck by lightning on a weekly basis, I wouldn't take my chances with showering during the storm either.

[lucioperca]

Install this, instead of a light in the bathroom: https://en.wikipedia.org/wiki/Lightning_rod

[mschuster91]

In a lightning strike, electricity doesn't exclusively follow the lightning rod. That's the problem.

The major part of the current will flow through the rod, but a small remainder can and will cross into the house - TV/radio/sat antennae and overhead electric/phone wires are the main culprits here, but belowground cables and water/gas/metal sewer pipes can also serve as a point of ingress.

Normally you're supposed to have proper grounding at each of these ingress points as well as surge protectors, but all it takes is for one of the grounding connections to be a tad bit loose or a SPD being expired due to prior overvoltage events, and suddenly the pipes or whatever can pose a significant enough voltage differential to the rest of the house to kill you.

And if that news isn't bad enough, most people (especially landlords) do not care too much about their electrical and other wiring in the home. Every few years you should re-tighten wire connector screws with a torque wrench to make sure the connections are still up to the spec of the manufacturer, and grounding rods need to be regularly measured as well, particularly after drought periods to make sure they haven't dried out in the time since the last check/construction.

[AdamN]

I did a home inspection on my house and really appreciated the insights there - many hazards were identified and it makes doing a rational de-risking exercise possible.

[spdustin]

Or heaved out from freeze-thaw cycles, an excellent sign that it was nowhere near long enough in the first place.

[spdustin]

The difference in expected utility from showering (either during a lightning storm or not) is minimally affected by the choice to postpone it. That's why I'm content to call it a binary rule.

The choice of showering/bathing at all has a different risk profile, yes, and also a different expected utility. Comparing the two is a false equivalence.

Statistically speaking: our kids (and their parents) simply enjoy watching storms, and we all choose to shower when the risk of lightning is zero. That choice maximizes utility, as our subjective enjoyment of the light show isn't diminished by postponing something as pedestrian as a shower for an hour.

[lucioperca]

You could improve the grounding instead of spending time making such a light.

[dekhn]

I have not found that arguing with lightning-is-death folks to be particularly successful.

[imp0cat]

That is easier said than done, especially in an old house.

[jajko]

But its still a massively better approach long term rather than making up some hacking project, quadruple that if one owns the place. I mean sure its nice to see such creativity, but in our lifetimes how often do we see some... lets say a bit different folks being obsessed in one topic, neglecting all other aspects or much simpler, yet less 'hacked on my own' solutions.

I mean it literally, one example out of endless sea - a peer making some VR game about collecting virtual balls by vacuuming over them in pacman style, across whole apartment, so kids do the work. Instead of learning children to accept the suck a bit since life will bring you millions more such situations, man up and just do it, without additional external motivation and hand holding. But he wanted to play around with tech primarily, not thinking much about potential consequences (kids outright refusing activities that aren't fun and strengthening this mindset). Of course that vacuuming is also pretty crappy at the end, instead of thinking 'there is corner / weird place that I should cover too', they just run quickly through all virtual balls, missing the core reason for vacuuming.

[imp0cat]

Agreed, the correct approach is definitely: "fix the core issues properly!".

It's just not as easy as slapping together a warning sign about incoming storms.

[codersfocus]

Why do you use spoons, forks or knives? Just man up and use your hands wussy.

[sadcherry]

Do you have any statistics about lightning-related injuries or deaths in showers?

[wickedsight]

I had to look it up, because this seems like a pretty unrealistic fear to me. What I fond:

> less than 1 in 1 million chance of being struck by lightning directly or indirectly

> One-third of all lightning injuries occur indoors.

I'm pretty terrible at statistics, but I think we can assume that there's a less than 1 in 3 million chance to be injured by lightning indoors.

But lightning related injuries indoors could also be from a window exploding after lightning hits a tree outside, or a fire related injury from a lightning strike to the house.

So what's the chance of being hit by lightning in the shower? And then being seriously injured?

Snopes lists 4 examples of people being hit by lightning in the shower, spread over 20 years. All of them with minor injuries. The chance of major injuries is also much lower than with a direct lightning strike.

So finally, is the 'safe to shower' thing useful? I'd say that making this is probably time that could've been spent on more useful safety related things.

Also, if it's just 'is it safe to shower?', it ignores tons of other dangers inside the house during thunder storms. Touching any tap, corded appliance, concrete wall or floor or being near an outlet is just as dangerous as being in the shower and none of those things are particularly dangerous in the grand scheme of things!

[lolc]

Not to disagree with you general point, but applying general risks to specific situations is not proper use of statistics. Once a thunderstorm is on, the risk just multiplied from the baseline risk for the people in the area. And it grows again for people who take a shower.

[wickedsight]

Well, guess that's why I started with the fact I'm terrible at statistics!

[danbruc]

This [1] is the best I could find with a quick search, admittedly far from ideal, but it has some numbers to start with and might help to locate better data.

[1] https://www.independent.co.uk/news/science/it-safe-take-show...

[optymizer]

I don't know about this approach. Seems a bit panicky / heavy-handed to turn this particular risk into a "judgment call" compared to all the other risky things kids do. Could just be an occasional conversation / reminder:

- "We can't take a bath / shower right now. There's a big lightning storm outside." - "Why not?" - "The lightning hits the ground and it can spread through the water. It's not safe." - "OK"

Is it really worth teaching kids to check this signal every day, instead of having this conversation like twice a year?

If the kids had to check multiple things before showering, this light would simplify the decision making process, but by the sound of it, it's redundant.

If it's unsafe enough not to shower, you'll probably hear the thunder too. There's your signal not to shower.

Though maybe it's not like that and the kids enjoy it.

[spdustin]

It storms a lot here. And kids are notorious for not hearing things that are obvious to the rest of us. :)

My kids aren't paranoid, they don't freak out about the storms. It's just a natural thing, and a reminder that there's a potential that nature's best light show is in store for them. A nice side effect is that they're not afraid of storms—they look forward to watching them.

[phoronixrly]

Ok, blanket advice from US governmental agencies and a Mythbusters episode with electrical and water installations that seem... Very DIY and not up to code? I mean it is mythbusters... IDK.

I suspect power outage in the shower is more dangerous in my case than any other electrical issue... I guess it may be more of a US issue, especially since I am not finding any advice from EU agencies on the matter?...

[spdustin]

Building are different in different countries, and other geopolitical divisions. The UK authorities, for example, say it's safe to shower during a storm as long as your plumbing has been properly integrated into a standards-compliant equipotential bonding, noting that said standards change over time. So, you'd have to know them and trust/verify the builder followed them.

Or, you know, just wait a while and enjoy the show.

Whatever. You do you.

[Spivak]

But is there any risk to you being in the path of least resistance? All your pipes are connected (to the ground) so why would the electricity not take the readily available metal path?

[spdustin]

The risk of death of showering during a lightning storm could be the same as the risk of death going for a 15 mile drive[0].

A typical lightning bolt is about 300 million Volts and about 30,000 Amps. Since even the best-grounded home certainly can't sink 30,000 amps of current into the neutral-bonded earth bar, it has to go somewhere. It finds multiple paths, and the current is shared between them. There's also the conversion to heat in all those insufficient conductors, etc.

[0]:https://www.independent.co.uk/news/science/is-it-safe-to-tak...

[icehawk]

Electricity doesn't only take the path of least resistance, it takes all paths available in inverse proportion to their resistance (impedance really.)

And since the water and sewage systems are plumbing systems and not electrical systems, its highly likely they'd be at different electrical potentials in a strike.

[therein]

I think they don't trust the grounding or the house doesn't have proper grounding.

Either way should be easy to test. Run the showers and excite the paratoner.

[spdustin]

I learned long ago not to trust corporate homebuilders.